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Discussion Starter #1
I've read for three years now that the '04 Z06 shocks are the way to go for older Zs, but now with the improved shocks for the '07 Zs, are they a better alternative, or should I still go with the '04s? Looking for improvements for both street and road course use.
 

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You should ask what are the best shocks for the money you are willing to spend. The C6Z06 shocks are probably the cheapest shocks you can buy and will probably be better than what you have. 04 shocks cost about twice as much and provide similar performance, but they're still relatively cheap at less than $100 each. I haven't read anything where someone said one is definitely better than the other.

If your budget is bigger you have more choices and will get better performance. You should also consider whether or not you'll notice the difference between $400 shocks and $4,000 shocks. If you have an unlimited budget but you're not an experienced racer you can go to a race shop, have them install and set up what ever shocks they suggest. That will give you great performance, but will probably cost $6,000.

There is no best shock. Only the best shock for you.

Dog
 

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I have no back-to-back comparo on '04 C5Z vs C6Z shocks; however, I chose '04 C5Z because I didn't know the spring rates for the C6Z and was sure that the '04Z would be tuned to the C5Z suspension. One day at Summit Main, two days at VIR full, one day at Summit Shenandoah North (Carousel) and I'm happy ... :thumb:
 

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I have LGs coilover kit, and I have to say they are completely awesome. I'm sure adjustable Penske's are better, but they cost a fortune. I've heard a lot of talk about leaf spring/coilovers on this site. For me, coilovers were a 'huge' upgrade on the car. Definitely one of my favorite upgrades.
 

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I have no back-to-back comparo on '04 C5Z vs C6Z shocks; however, I chose '04 C5Z because I didn't know the spring rates for the C6Z and was sure that the '04Z would be tuned to the C5Z suspension.
I have to agree... the development of the '04 C5Z shocks was done on the C5Z with its specific weight distribution and spring/roll bar rates. Unless there's some new "technology" incorporated into the C6Z shocks (likely not or GM would have advertized it), then my bet is the '04 C5Z shocks are going to work best with an otherwise stock C5Z suspension.

I've also heard good things about the new Koni FSD shocks, with people reporting they are a great shock for mixed track/street driving as they provide more compliance over sharp bumps. Whether or not they would be an advantage on the racetrack compared to the '04 C5Z shocks remains to be seen. I'd bet the C5Z shocks may be a better "track only" shock since that's where they were developed.
 

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I have to agree...

I've also heard good things about the new Koni FSD shocks, with people reporting they are a great shock for mixed track/street driving as they provide more compliance over sharp bumps. ....

I forgot about the next price step up from the 04 shocks, the Koni FSD's. Grassroots Motorsports just started a C5 project car and reported great results with the FSD's as a stock non adjustable replacement. I think they're less than $700.

Dog
 

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Koni are an outstanding shock, very well respected in the road racing circles. I haven't driven a Vette with Konis, but I plan to put these on if I can't round up the money for Penskes, based on Koni's overall reputation.
 

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I have had the Koni FSD's on for a bout 6 months and love them! This is one mod I would do again in a heartbeat! :cheers:
 

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Discussion Starter #9 (Edited)
Thanks to all for your insite and knowledge shared to this point. Although I was mostly interested in comparing the best oem C5 and C6 shocks, particularly since the C6Zs have a significant price advantage, I purposely worded my question vaguely enough to try and draw in opinions of other options available. I too have seen the Grassroots Motorsports build, and am very interested in opinions on the FSDs compared to the oems. Meldog, I agree completely that it's a "what's right for me" situation. I am not on an unlimited budget, and admit to being intrigued by the newer shocks being that much cheaper. Sometimes you get what you pay for, but sometimes a real bargain can be available, and you've got money toward other mods. Obviously the Penskes are wonderful from all reports, but that is way out of my budget. Also, the coilovers offer fascinating possibilities as far as corner weighting and other areas, but again, more than I'm looking to spend now. I am interested in how either are superior for the sake of having the knowledge, but primarily now I want to know can the newer cheaper C6Z oem shocks work better than the older, more expensive C5Z oems on a C5Z? I assume most have read the C&D article on how the latest C6Z shocks transformed the car and knocked 3 seconds off of their lap times at VIR, but how would that carry over to the C5, expecially compared to the '04 package? Are the Konis, Bilsteins, or any other aftermarket that are within shouting distance price wise going to out perform the oems? Thanks again for the opinions expressed so far, and please continue to weigh in with any further ideas!!!!!
 

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As previously mentioned, I can't really offer any further info regarding the OEM shocks other than my own speculation, but you may be interested to read this thread from the other forum:

http://forums.corvetteforum.com/showthread.php?t=1735838&highlight=koni

There's some good info on the Koni FSD shocks as well as the spring rates for different OEM C5 suspensions including the FE4 (Z06), T1 race, and Hyperco aftermarket springs... it took me a few posts to extract the info I was looking for, but I eventually got it!:drunken:

My path now is to upgrade to the T1 springs and sway bars (which I already own, bought used) and the Koni FSD shocks. This setup likely won't perform as well on the track as a dedicated race-oriented suspension (like properly set up coil overs), but will be a significant step up from the stock '02 FE4 suspension and should flatten the car out during dynamic maneuvers with little-to-no ride quality penalty, possibly even an improvement in ride quality from what I've read from others so far.

An improvement in ride quality is something that few racetrack suspensions could claim I'm sure...

This may or may not be what you're looking for, just some food for thought and some interesting technical info.
 

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Discussion Starter #12
Blue Angel and DennyM,

Thanks for taking the time to input, and for the links provided. RouschRaven had some good input and encouraged even more from others. Wondering about the FSDs on stock springs, not lowered, or at most, stock bolt lowered. Do you suppose that the "bounciness" he experienced would be better with that scenario?
 

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I have to agree... the development of the '04 C5Z shocks was done on the C5Z with its specific weight distribution and spring/roll bar rates. Unless there's some new "technology" incorporated into the C6Z shocks (likely not or GM would have advertized it), then my bet is the '04 C5Z shocks are going to work best with an otherwise stock C5Z suspension.

I've also heard good things about the new Koni FSD shocks, with people reporting they are a great shock for mixed track/street driving as they provide more compliance over sharp bumps. Whether or not they would be an advantage on the racetrack compared to the '04 C5Z shocks remains to be seen. I'd bet the C5Z shocks may be a better "track only" shock since that's where they were developed.
I agree that the '04 shocks are the best for an otherwise stock suspension. I've also heard good things about the Koni - but no side-by-side comparison.
 

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Ken asked me to comment here.

Per application:

Street only:
- C5 Z06 = install the '04 shocks
- C6 Z06 = OEM are adequate
NOTE: the C6 Z06 shocks have a shorter travel and are not recommended on a C5 Z06 unless the car is lowered. The C6 Z06 shock has some marginally improved valving over the '04 C5 shock.

For the track (includes AutoX, road course and Drags) and IF you have maximally lowered past the factory recommendations:
You need to go with a shorter shaft/body shock. Preferably an Aluminum body mono-tube racing shock that has seperate Bump and Rebound adjusters and a remote reservoir which can be adjusted while on the car easily and without hassle or special tools. It should also mount opposite aOEM shock (up-side-down) to reduce unsprung weight.
Additionally a dual use (street & track) car benefits from a wide range DA shock as it sees so many different road conditions IE... AutoX vs Street vs Interstate vs Road Course vs Drags vs Ovals vs wet & dry conditions on all these surfaces. A narrowerer range valving should be used for a dedicated AutoX or dedicated road course car biased for use.

I do not recommend QA1 shocks which are on offshoot of the old Carrera shock technology. Although they apparently work well in Drag applications only

Bilsteins and Koni's offer only marginal gains over the OEM shocks and in the past have offered only steel body shocks, non-adjustables or adjustables that did not have seperate channels for Bump and Rebound adjustment, no remote reservoir, needed to be adjusted off the vehicle, etc., etc.

Penske, JRZ and Moton have the best value DA shocks. Penskes are US made while JRZ & Moton come from Holland & Belgium, which has led to supply and parts problems in the past. All three are totally rebuildable and revalvable and will outlast the car.

I recommend The Penske/Mallett's as Mallett has the best mounting and lines to the remote reservoir. These can be easily upgraded to 3 way adjustables, a third spring active suspension and/or coilovers.

Both JRZ and Moton have a cheaper sport (vs race) model but I wouldn't waste time or money with them. Get the race ones if you go that way.

Don't look at price points only but performance and ease of use as the most important points. Note the initial cost, while higher, can easily be recovered with an increased value when the car is resold if if taken off and resold seperately. Note that while paying an initial $3,000 for the Penske/Malletts I have recently resold a 4 year old set for $2,000 and a 3 year old rebuilt set for $2,500. That works out to $47 /shock/year. Really not expensive at all.

To answer the question of the post: The best shocks available today are the Moton 4 way adjustables; @ $10,000 per set or $10,500 in coilover as used on the C6R. This makes the Penskes look even more cost effective.

A note on coilover shocks: I do not recommend nonadjustable shocks be used in a coilover set up. Remember each car is different with different corner weights and each spring rate has to be tuned differently.
 

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Blue Angel and DennyM,

Thanks for taking the time to input, and for the links provided. RoushRaven had some good input and encouraged even more from others. Wondering about the FSDs on stock springs, not lowered, or at most, stock bolt lowered. Do you suppose that the "bounciness" he experienced would be better with that scenario?
Thanks for the mention. For my use, I find the Koni FSDs and Hyperco - streets springs to be the perfect combination.

Regarding your question, I don't have any first-hand knowledge however others have remarked that ride and handling improved over '01-04 shocks(adjusters at stock riide height).

-RR
 

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Discussion Starter #17
To all involved, the knowledge and opinions based on experience offered here far exceeded my hopes and expectations. A personal note of thanks to DJWorm for responding to a request to weigh in. Your depth of technical understanding and the willingness to share it never cease to amaze me. Thanks also to roushraven for noticing the conversation and adding to his previous input from "the other forum". Will continue to monitor for any further additions.
 

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DJ worm, to Revive old thread. Been on 04 Z shocks for several tracking years. any benefit to going to C6 or C7 Z06 shocks? Car is lowered on stock bolts and I use T1 swaybars, too. So busy with students that I don't get to pay really close attention to handling improvements. I run the Ridge Motorsports Park, and Pacific raceways. Ridge is smooth, Pacific has a few bumps, and polished surface.
 
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